Solid absorbents capable of removing oxygen from air are being considered for on-board oxygen generation systems for aircraft. Among the compounds suggested for use are certain cobalt chelates, particularly bis(3-fluorosalicylal)ethylenediimine cobalt (II). While the cobalt chelate has the capability of absorbing and desorbing oxygen, volatilizable inert materials are formed under the conditions prevailing during the absorb-desorb cycles. These inerts occupy oxygen sites, a condition which renders a portion of the absorbent unsuitable for further use. Furthermore, the processing conditions under which the cobalt chelate is prepared are condusive to the formation of volatilizable inert materials. As a result, oxygen sites of the material after manufacture are occupied by volatilizable inerts, thereby decreasing the capability of the cobalt chelate to absorb and desorb oxygen.
It is an object of this invention, therefore, to provide an improved method for generating oxygen.
Another object of the invention is to provide a method whereby volatilizable inerts are removed from a cobalt chelate oxygen-absorbent prior to and after use in the generation of oxygen.